This trial is registered as ISRCTN88318003.
Funding
Funding for this study was primarily provided by the Health Technology Assessment programme of the National Institute for Health Research, with additional financial support received from Comprehensive Local Research Networks.
Chapter 1 Introduction
A
sthma affects> 5 million people in the UK and costs the NHS in excess of £1B. Althoughpharmacotherapy is effective and can provide full control for some patients,1surveys repeatedly show
that outcomes remain suboptimal. A recent European survey showed that fewer than half of adults with asthma achieved good symptom control2and that quality of life (QoL) is affected for most, with consequent
costs to the community both directly from health service use and indirectly from lost productivity. Many patients have concerns about taking regular medication, particularly inhaled corticosteroids. Surveys of complementary and alternative medicines in asthma show high levels of use, with up to 79% of adults and 78% of children reporting trying different treatments, include breathing modification.3Breathing techniques
are among the most commonly used complementary techniques, with up to 30% reporting having used them to control their symptoms.4The James Lind Alliance and the patient organisation Asthma UK have
both identified breathing exercises for asthma as a priority area for research.5Asthma encompasses a variety
of phenotypes and different therapeutic approaches may be effective in different patients.6Symptoms
attributed to dysfunctional breathing have been reported to be more frequent in people with asthma than in the general population.7,8A number of controlled studies have investigated breathing modification
techniques and have reported beneficial outcomes. Breathing control techniques investigated have included the Butekyo breathing method9–13and yogic breathing.14–16Recent studies have shown clinically important effectiveness of physiotherapist-administered breathing exercises for people with asthma in the UK.17–19The evidence base for the effectiveness of breathing therapies for treating asthma has been assessed in several reviews. A recent systematic review of the effectiveness of physiotherapist-taught breathing retraining was carried out as part of a review of physiotherapy interventions in the treatment of respiratory diseases in adults.20This was a collaborative multidisciplinary review undertaken by the British Thoracic Society (BTS)
and the Association of Chartered Physiotherapists in Respiratory Care (ACPRC), the respiratory clinical interest group of the Chartered Society of Physiotherapy (CSP). Its purpose was to critically appraise the evidence for respiratory physiotherapy techniques in respiratory diseases and it used an explicit evidence- based methodology. This consisted of an initial literature search, conducted by the Centre for Research and Dissemination (CRD), York, UK. Papers and abstracts identified were appraised and graded by two trained assessors using Scottish Intercollegiate Guidelines Network (SIGN) methodology, with recourse to a third assessor in the event of disagreements. The review found that‘Breathing exercises, incorporating reducing respiratory rate and/or tidal volume and relaxation training, should be offered to patients to help control the symptoms of asthma and improve QoL (Grade A)’. In the latest iterations of both the BTS/SIGN UK national asthma guideline21and the World Health Organization (WHO)-endorsed Global Initiative for Asthma (GINA)
guideline,22breathing exercises are endorsed as adjuvant treatment for people with inadequately controlled
asthma despite standard pharmacological treatment. Previous research from members of this study group has provided evidence supporting this recommendation. A prior Cochrane review of breathing exercises for asthma was performed in 2004,23before several large studies informing the BTS review had reported. This
review stated that, because of the diversity of breathing exercises and outcomes used, it was impossible at that time to draw conclusions from the available evidence. The review stated that trends for improvements were noted in a number of outcomes and that large-scale studies were warranted to clarify the effectiveness of breathing exercises in the management of asthma. Subsequently, Slader et al.3reported a double-blind
randomised controlled trial (RCT) of breathing techniques in asthma and concluded that breathing
techniques may be useful in patients with mild asthma who use a reliever inhaler frequently. This Australian study investigated the effects of two different breathing retraining programmes taught by physiotherapists and delivered as videotaped instruction programmes that the participants completed at home, without face-to-face supervision. Both programmes were associated with improved health status and major reductions in bronchodilator use compared with baseline values.
These instructional interventions have subsequently been made available as internet downloads and have been used in Australia to improve asthma control in routine clinical practice. This study provided provisional evidence that breathing retraining programmes delivered in a self-guided audio-visual format are feasible and may potentially produce beneficial outcomes in asthma. A 2007 UK primary care-based
DOI: 10.3310/hta21530 HEALTH TECHNOLOGY ASSESSMENT 2017 VOL. 21 NO. 53
© Queen’s Printer and Controller of HMSO 2017. This work was produced by Thomas et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.
RCT18demonstrated that breathing retraining taught by a physiotherapist in face-to-face sessions
significantly reduced respiratory symptoms and improved health-related QoL compared with usual care. The population studied consisted of community-treated asthmatics with mild and moderate disease. The contents of the breathing retraining programme in this study were very similar to those in our study, but only face-to-face instruction was investigated and no economic analysis was carried out. A Canadian RCT published in 200813added further support for breathing retraining in asthma, also finding significant
reductions in asthma symptoms. In this study, a breathing retraining intervention delivered by physiotherapists in a face-to-face setting was compared with the Butekyo breathing method (also taught in face-to-face sessions by a therapist). Large magnitude but similar improvements in health status and symptoms from baseline levels were seen in both treatment arms.
A further RCT published in 2009 investigated the effects of a physiotherapist-delivered breathing retraining intervention, with similar content to that included in the face-to-face arm of our trial.17This study controlled
for the non-specific‘placebo-like’ effect of professional contact and sympathetic attention by giving the control group the same amount of professional contact time (with an experienced respiratory nurse providing asthma education). Significant improvements from baseline were seen in patient-reported asthma outcomes for both treatment arms after 1 month, with trends favouring the breathing retraining group; at 6 months a large and significant difference between treatment arms was found in favour of breathing retraining. Significant improvements were seen between treatment arms in asthma-related QoL, anxiety and depression and Nijmegen questionnaire scores (measuring hyperventilation-related symptoms) and a trend was seen for an improvement in symptomatic asthma control. No effect on airway inflammation or physiology was found. No economic evaluation was carried out.
The addition of these subsequent trials to those in the Cochrane review23as part of the BTS review20led the
authors to conclude that the evidence supporting breathing retraining for people with asthma was of 1++ strength. However, no recommendation on the most clinically effective or cost-effective way of providing breathing retraining was made. Most of the studies contributing to the evidence base involved face-to-face interventions and it is here that the evidence is strongest. Only two preliminary studies have investigated the use of instructional interventions delivered by videotape or DVD,9,14with some evidence that this modality
may also be effective. To our knowledge, no previous studies have compared a DVD breathing retraining intervention with a face-to-face breathing retraining intervention. In our study we aimed to assess the effectiveness of the intervention not only in comparison with usual care or a placebo but also in comparison with an intervention of known benefit. The logistic and economic implications of making this intervention available to all who could potentially benefit in the UK through a face-to-face physiotherapy programme are considerable. We felt that if comparable effectiveness could be shown for a self-guided breathing retraining programme, this is likely to provide a more efficient, convenient and cost-effective service to patients. The available evidence prior to this study suggested that a programme of breathing retraining consisting of three or more face-to-face sessions delivered by a specialist respiratory physiotherapist was effective in improving patient-reported end points, particularly health status (the outcome measure that most accurately captures patient experiences and QoL impairment) and psychological well-being, for people with asthma, and may be effective in reducing rescue bronchodilator medication usage. There were suggestions that similar beneficial effects may be achieved through the use of self-guided interventions instead of face-to-face instruction. However, the relative clinical effectiveness and cost-effectiveness of different approaches to breathing retraining have not been adequately assessed. If similar benefits could be demonstrated without face-to-face contact with a health-care professional, the health resource implications of providing breathing retraining would be improved and this intervention could realistically be made available to the many people with asthma who could potentially benefit from it. Therefore, we proposed to transfer the key components of the physiotherapist-delivered programme that we (and others) have shown to be effective into a self-guided format (delivered in this study through a DVD, but able to be delivered through internet-based technologies) and to compare the effects of this intervention with those of face-to-face sessions with a physiotherapist and with usual care. Our study included a full health economic evaluation, as previous research has focused on the clinical effectiveness, rather than the cost-effectiveness, of breathing retraining. We also included qualitative research to capture patient perspectives on the interventions and a full process evaluation.